Many foreign ministers occasionally feel that they have to look in all directions at once but Prince Saud al-Faisal, the urbane, Western-educated Foreign Minister of Saudi Arabia, could be forgiven were he in a state of permanent distraction.

"Saudi Arabia is a Gulf country," he observed, "but it is also a Red Sea country and a Middle Eastern country." The kingdom is still reeling from the financial and social effects of the 1991 Gulf war. It is playing a low-key part in edging forward the Middle East peace negotiations that began with the Madrid conference and it is encouraging Israel and the Palestinians to solidify their deal. "Our com m itment is there because we have a stake in the peace," Prince Saud said, "even though quite honestly the Israelis are going against the spirit and the letter of the agreement."

At the same time the Saudi monarchy continues to play the murky game of inter-Arab politics, armed with a slightly thinner cheque book and the unspoken but effective shield of American military support.

Two critical questions confront Saudi Arabia. The first is whether it can keep its domestic political structure intact. The second is whether the vast quantity of arms it buys from the West can ever satisfy what one academic has aptly called its "ceaseless search for security".

Both issues are of concern to Britain. During a lengthy interview in his office at the foreign ministry Prince Saud sketched out the concerns the Saudi government harbours about its security and - by Saudi standards - gave an unusually frank public assessment of its priorities.

"One thing we can safely say," said Prince Saud, "is that the threats to security and stability in the Gulf do not come from outside but from within the region." That is Saudi diplomatic code for the twin worries of Iraq and Iran.

Like other ministers and senior members of the royal family, Prince Saud played down the impact of fundamentalist opposition at home. But he did not conceal the kingdom's continuing worry about its unpredictable neighbours. It is clear that the focus of Saudi concern has shifted away from Saddam Hussein's broken and bankrupt Iraq. In conversations with ministers, bankers, oil industry experts and political analysts one consistent new preoccupation emerged: the future of Iran, whose oil economy is in decay and whose revolutionary government is facing dissension and international isolation.

"We have tried to improve our relations with Iran in spite of the fact that there are real problems," said the minister. "All the Gulf Co-operation Council states have tried to establish excellent relationships with Iran."

Despite these protestations, the GCC is set on a collision course with Tehran over Iranian claims to three islands in the Gulf which are also claimed by the United Arab Emirates. The dispute has been taken to the International Court of Justice but it is being seen in the Gulf as an ominous sign of Iranian assertiveness.

Nor can the Saudis forget the violent history of Iranian participation in the annual Haj pilgrimage to Mecca, for which each side blames the other.

According to the Interior Minister, Prince Nayef bin Abdul Aziz, the Saudi authorities four years ago detected a group of would-be revolutionaries who, he said, had received weapons and explosives training in Iran. And while Prince Nayef said there was no evidence of Iranian involvement in the recent fundamentalist campaign, the Saudis remain irritated by a constant stream of rhetoric fromTehran Radio, excoriating the royal family and praising its radical Muslim foes.

That, no doubt, explains why the Saudi cabinet set national security and defence at the head of its priorities in the new five-year development plan. That, it is publicly claimed, justifies the need for enormous expenditure on arms from the United States, Britain, France, and Brazil.Officially, defence spending consumes 30 per cent of the Saudi budget but economic analysts in Riyadh believe the real percentage could be much higher. Prince Nayef insisted that budgetary constraints would not impede the purchase of foreign weapons. Nor, it seems, will scandals abroad, over commissions and shady dealings by Western politicians and businessmen, interfere with the trade. Prince Saud repeated that "these are contracts between governments and no outside agencyshould come into it".

Relief might be expected to greet these remarks at the British Embassy and in the numerous discreet installations set up by British Aerospace to oversee its part of the controversial £20bn al-Yamama arms deal.

But despite the confidence of the Saudi royals and the Western contractors falling over themselves in the rush to the new Middle East arms race, many diplomats whose countries are not involved in arms sales speak openly of their disquiet.

"It's cynically about money and not about regional security," said a European envoy in Riyadh. "The Saudis are being sold equipment that is overpriced, over-sophisticated and frankly of little use to them in a real military crisis." Another diplomat said: "Look at the air force - they don't even have the pilots to fly all these planes that you British are selling them. The only thing I can say is that the Americans are worse - one moment the Treasury Secretary is telling King Fahd to cut his budget and the next day Clinton is on the phone persuading him to buy more weaponry."

British and American officials respond to such criticism with well-reasoned strategic arguments. But the bottom line is that the Pentagon disburses at least $10 m every day to US defence contractors in payment for Saudi orders. And in Britain the al-Yamama deal is vital not only to British Aerospace but also, argue some analysts, for the entire UK defence industry. "The way we see it," said another critical diplomat, "is that the Saudis are keeping your defence production lines alive and these deals with the US and the UK are the payoff for military protection you provide against Iraq or anyone else."

The arms sales encapsulate both the domestic and external problems of the Saudi government. Muslim fundamentalists at home and in exile decry the deals as a source of corruption and they criticise the ever closer military relationship between Riyadh and Washington. This raises a fundamental question. Will the delivery of arms that are supposed to ensure the stability of the Saudi regime actually undermine it? To this conundrum, not even the smoothest British official can provide a convincing answer.

The rush to sell arms into the Gulf is a far cry from the diplomatic wisdom that prevailed in the aftermath of George Bush's war against Iraq. Then the talk was of a regional security, restraint in the supply of weapons and the creation of institutions to build confidence among distrustful nations.

Western officials seem to have succumbed to a fit of collective amnesia over these worthy aims. They have exchanged the vision of a stable Middle East for a random selection of policies held together by hope and chance: the success of the Israel-Arab pe a ce process, the "dual containment" of Iraq and Iran and the repression of revolutionary Islamic fundamentalism. All, to a greater or lesser extent, depend upon the continued stability of the kingdom of Saudi Arabia. Diplomats would hate the suggestion th at they might be betting men. But in counting on the House of Saud, Western strategy is based on a one-way bet.